1. Field of the Invention
The present invention relates to a NTSC/PAL compatible luminance/chrominance signal preprocessing device, and more particularly to a preprocessing device of a system that can record and reproduce the luminance and chrominance signal separated from the composite signal of a digital video tape recorder (VTR).
2. Description of the Prior Art
Generally, there are composite broadcast systems and component broadcast systems employed to transmit television signals. At present, television broadcasting utilizes a composite system which uses band compression technology. However, it is very hard to completely separate the chrominance signals from the luminance signal, and thus picture quality deteriorates due to mutual interference. In the component system, however, the luminance signal and chrominance signals are transmitted through separate lines, so that it is possible to prevent picture quality deterioration. In addition the bandwidth of the signal is wider.
Table 1 below shows sampling frequency (B) and recording method (C) according to the input signal (A) in a digital VTR.
TABLE 1 ______________________________________ Input Sampling Recording Standard Signal(A) Frequency(B) Method(C) ______________________________________ 1 composite 14.3 MHz(4 fsc) composite 2 10.7 MHz(3 fsc) component luminance: 13.5 MHz 4:2:2 3 component (R-Y): 6.75 MHz component (B-Y): 6.75 MHz ______________________________________
Present digital VTRs generally follow the number 3 standard, which facilitates mutual communication between the NTSC and PAL signals. However, since the input signal of the number 3 standard system is a component system, a problem arises in that users cannot use television sets or monitors that utilize the composite system employed by present television broadcasting.